I originaly thought my crashed to a limited RAM (2g) Yet, even with a new box with 6g RAM, the game still goes down after an hour. From the Event Viewer:
Faulting application name: Oblivion.exe, version: 1.2.0.416, time stamp: 0x462392c7
Faulting module name: Oblivion.exe, version: 1.2.0.416, time stamp: 0x462392c7
Exception code: 0xc0000005
Fault offset: 0x001ea353
Faulting process id: 0xf40
Faulting application start time: 0x01ce29e068f5e1e4
Faulting application path: C:\gamesas\Oblivion\Oblivion.exe
Faulting module path: C:\gamesas\Oblivion\Oblivion.exe
Report Id: 806a31d4-95d5-11e2-9d48-f0def1b7abc4

Also imediately preceeding:
"The content source cannot be accessed."

Has there ever been a bugfix